Grinding mill of the swing-hammer or beater type



, 7,' 1930. )J. P.. VAN GELDER 1,777,905

GRINDING HILL OF THE SWING HAMMER OR HEATER TYPE Filed July 29, 1929 Patented 00b7, 1930 A EN OFF-[CE j JOHANNES ETER vim .GELDER, orcRAnvILLE, NEAR sYnNEY," nEwfsoUrH-wALns;

Y AUSTRALIA- y a "I .GBINDINQ'GMILL OFTI-IE SWING-HAMMER. on B ATER 'rvrn f J Application filed J ui ze, ieas/seriarrd. 381,824, and in Australia August 16, 8;

This invention relates to grinding mills of swinghammer or beater type from whlch the ground product is" delivered through screenstwhich retain the oversize particles. It has been devised to obviate practical difficultles which are encountered more partlcularly when screensv of finegauge are used; such screenswhen fitted 1n the beater chamher have not. the necessary@mechanical strength for withstanding the impact and attrition offlying particles of stock under treatment.

"In mills according to the present inventlon, the screen 1s fitted 1n a screenlng chamber inone of the end covers of the beater chamber, and deflector blades are fitted on the overhung end of the mill shaftin the screening chamber to deflect coarse particles I is overhung. Swin hammers or beater arms The base part of this screen is fully open to are fitted on the shaft within the beater cham- -vat1on.taken through the beater chamber. chamber through a tangentially disposed and the shaft bearing seat 12 arelintegral.

her and the feed is taken into the. beater vent in the end cover of the chamber which is contiguous to the shaft bearing.

The screen is contained ina separate'chamher which is an endwise extensionof the beater chamber and is fully open thereto. In

the screen chamber a lantern frame is set up to carry a frustro-conical shape ring screen.

the end of the beater chamber and the overhanging end of the shaft projects into" it. Upon thispart of the shaft two or more blade headed arms are fitted, the blades being disposed angularly to the shaft axis; these blades sweep over the interior face of the screen annulus but do not touch it. The fine material which the screen passes goes into the end of the mill chamber in which the screen is housed, and'falls thence down through a bottom delivery vent.

As grinding proceeds, the finer product is "and the centrifugalblast efiect ofthe bladed 7 arms in thescreen" chamber operate to facilitate passage ofthis fine product through the screen. The coarser 'particles which i the screen willnot'pass are whirled the blades r and by reason of the angular disposition of the bladesthey ar deflected back into the beater chamber where theyundergo further reduction, and ultimatelypass back'to the screen. i

The theparticles uponthem or to destructiveat:- tritionby coarse particles, and they are kept free for passing fine grade product. The

capacity of a mill onthis principle is high, assurance of uniformity of grade of product is obtained, and a material saving is effected becausethe screens are notinjured, and stoppages for makingscreen replacements are oh- 7 viated." i

. In "the accompanying drawings Fig. 1 is a vertical longitudinal sectional elevationofthemill; and l g Fig. 2 is a vertical transverse sectio'na-lele- 10 is abed platewith which the casing 11 The shaft 13 is. carried in "the bearing 14 and the part of it which is within thecasing 11 tion, and preferably corrugated on its interior screens arenot subjected totimpact of is overhung. 15 is a linerring of torus sec- 1 face; Itis fitted within the beater chamber.

.16 is a lantern frame which is fitted within the Thedished sides of' {the V frame 16 and the end of it are clothed with wire gauze or perforated sheet or other suitscreen chamber.

able screen 17 of gauge appropriateito the grade of product required. The outer-end of the screen chamber. isclosed by a cover. 19,

and a vent 20is formed in the bottomofthat chamber. 21 are discs keyedon the shaft,and 22 are swing. hammers hung by pivots 23 between these discs. 24. are radialarms keyed on the overhang end of the shaft, and 25- are paddle bladespitched angularly, andfixed on these arms. 26 is a feed h opper, 27a pawl;

and detent type feeder driven by a belt 28 from the shaft, and 29 is the feed spout leading from the feeder into a port 30 in the inner end cover part 31 of the casin 32 is an access gate in the side of the casing.

In operation,thestockto be milled is charged into the hopper 26 and is delivered by the feeder 27 at an uniform rate into the feed port 30, whence it falls into the beater ring or ClTllITL It is there whirled and smashed by the action of the swing hammers, and the-finer part of the product passes into the screen, goes through the screen, and'passes out through the delivery vent 20. Thescreen is kept free by the air scour produced by the revolving blades 25, and particles which will notpass through the screen are swept back by these blades into the beater chamber to suffer retreatment therein. The frustro-conoidal shape of the screen facilitates this return of the coarser grade particlesto the beater chamber;

WVhat I claim as my invention and desire to-secure by Letters Patent is 2- v I 1. A swing hammer-0r beater typegrinding mill including-a casing-havingttwochambers one of which forms a beater chamber, afixcd screenof frustro-conoidal shape in/ he other chamber inthe. casing-the. sidewalls and one end of said screen being clothed with screening material, a shaftcnd overhung in the screen chamber, and angularly pitched blades carried on the shaft Within said=latter chamber and adapted for returningtothe beater chamber the .milledparticles which will not pass through the screen.

2. A grinding mill-comprising a-hori-zontally disposed. cylindrical casing, a torus ring liner occupying a portion of the length thereof to form a beater casing, a screen of frustuoconoidal shape occupying the remainder of the length of said chamber, said screen being of lesser diameter than theinterior of the torus ring liner, andhaving its sides and one end clothed with screeningmaterial, means for introducing the feed into the beater chamber, means for permitting removal of the screened product from the screen chamber, a rotatable shaft axially disposed in said casing, beating hammers swin 'ably mounted on said shaft adaptedto co-act With the torus 4. A swing hammer or heater typegrindin'g mill comprising a horizontally disposed cylindrical casing, a torus ring liner occupying a portion of the length thereof-to form a beater chamber, a lantern frame of frustro-conoidal shape occupying the remainder of the length 11 of the casing, a perforated covering on said frame, the frame being of lesser diameter than the interior of the torus ring liner, a rotatable shaft axially disposed in said casing, a hearing for the overhung shaft arranged externally of the casing, sWingha-mmers mounted on said shaftadapted to coact With the torus ring liner to pulverize the feed, arms extendingfrom the shaft and terminating in angularly pitched blades. for coacting with the screen, a feeder arranged on the casing for delivering measured quantities of feed into the closed end of the beater chamber, and adischarge vent at the bottom'of the chamber housing the lantern frame, substantially as and for the purposes set forth.

In testimony whereof I afiix my signature. JOHANNES PI'ETER VAN GELDER.

ring liner to pulverize the feed, and angu-larly pitched blades alsocar-ried on saidshaft, said blades adapted for promotingdischarge of fine product through the screens and for returning coarse product-to the beater chamher to effect repeated pulverizationc.

3. A grinding mill including a casing provided With two chambers, a feeder thereon arranged for deliveringmeasured quantities of feed into one of the chambers, a hearing at one end ofthe casing, a shaft ournaled-in the bearing'and projecting into the casing, a torus ring liner Within one of the chambers in the casing, hammers sWingably-mounte'd on the shaft for coacting with the ring liner, a

perforated Jun 

